Operation of a recirculation circuit for a fluid pump of a hydraulic fracturing system

Abstract

A control system may include a recirculation circuit configured to direct fluid from an outlet of a fluid pump of a hydraulic fracturing system to an inlet of the fluid pump. The control system may include a control valve in the recirculation circuit. The control system may include a choke valve in the recirculation circuit. The control system may include a controller configured to cause opening of the control valve to cause the fluid to flow through the recirculation circuit, and cause, based on a pressure of the fluid flowing through the recirculation circuit downstream of the control valve and the choke valve, actuation of the choke valve to maintain the pressure of the fluid below a threshold.

What is claimed is: 
     
       1. A pump system of a hydraulic fracturing system, comprising:
 a fluid pump having an inlet and an outlet; 
 a recirculation circuit configured to direct fluid from the outlet of the fluid pump to the inlet of the fluid pump, wherein a first pressure containment capability of the outlet of the fluid pump is greater than a second pressure containment capability of the inlet of the fluid pump; 
 a control valve, in the recirculation circuit, configured for actuation between an open position and a closed position; 
 a choke valve, in the recirculation circuit, configured to provide a pressure drop from a discharge pressure of the fluid pump; and 
 a controller configured to:
 cause opening of the control valve to cause the fluid to flow through the recirculation circuit; 
 obtain information indicating a pressure of the fluid flowing through the recirculation circuit downstream of the control valve and the choke valve; and 
 cause, based on the pressure of the fluid, actuation of the choke valve to maintain the pressure of the fluid below a threshold. 
 
 
     
     
       2. The pump system of  claim 1 , further comprising:
 a pressure sensor configured to detect the pressure of the fluid flowing through the recirculation circuit downstream of the control valve and the choke valve,
 wherein the controller, to obtain the information, is configured to obtain the information from the pressure sensor. 
 
 
     
     
       3. The pump system of  claim 1 , wherein the controller, to cause actuation of the choke valve to maintain the pressure of the fluid below the threshold, is configured to:
 cause increasing of fluid flow through the choke valve to maintain the pressure of the fluid at a maximum pressure that is below the threshold. 
 
     
     
       4. The pump system of  claim 1 , wherein the controller, to cause actuation of the choke valve to maintain the pressure of the fluid below the threshold, is configured to:
 cause decreasing of fluid flow through the choke valve to maintain the pressure of the fluid below the threshold. 
 
     
     
       5. The pump system of  claim 1 , wherein the controller is further configured to:
 cause closing of the control valve based on the pressure of the fluid being at or above the threshold and based on the choke valve being at a minimum flow position. 
 
     
     
       6. The pump system of  claim 1 , wherein the fluid pump is configured to discharge fluid to a manifold, and
 wherein the fluid discharged from the fluid pump is to enter the recirculation circuit upstream of the manifold. 
 
     
     
       7. The pump system of  claim 1 , wherein the inlet of the fluid pump includes an inlet manifold. 
     
     
       8. A control system, comprising:
 a recirculation circuit configured to direct fluid from an outlet of a fluid pump of a hydraulic fracturing system to an inlet of the fluid pump; 
 a control valve in the recirculation circuit; 
 a choke valve in the recirculation circuit; and 
 a controller configured to:
 cause opening of the control valve to cause the fluid to flow through the recirculation circuit; 
 cause, based on a pressure of the fluid flowing through the recirculation circuit downstream of the control valve and the choke valve, actuation of the choke valve to maintain the pressure of the fluid below a threshold; and 
 determine a difference between the pressure of the fluid and the threshold, wherein the actuation of the choke valve is based on the difference. 
 
 
     
     
       9. The control system of  claim 8 , wherein the controller is further configured to:
 cause closing of the control valve based on the pressure of the fluid being at or above the threshold and based on the choke valve being at a minimum flow position. 
 
     
     
       10. The control system of  claim 8 , wherein the control valve is upstream of the choke valve. 
     
     
       11. The control system of  claim 8 , wherein the controller, to cause actuation of the choke valve to maintain the pressure of the fluid below the threshold, is configured to:
 cause increasing of fluid flow through the choke valve to maintain the pressure of the fluid at a maximum pressure that is below the threshold. 
 
     
     
       12. The control system of  claim 8 , wherein the controller, to cause actuation of the choke valve to maintain the pressure of the fluid below the threshold, is configured to:
 cause decreasing of fluid flow through the choke valve to maintain the pressure of the fluid below the threshold. 
 
     
     
       13. The control system of  claim 8 , wherein the controller, to cause actuation of the choke valve to maintain the pressure of the fluid below the threshold, is configured to:
 cause actuation of the choke valve continuously to maintain the pressure of the fluid below the threshold. 
 
     
     
       14. The control system of  claim 8 , wherein the inlet of the fluid pump includes an inlet manifold. 
     
     
       15. The control system of  claim 8 , wherein the threshold is based on a pressure containment capability of the inlet of the fluid pump. 
     
     
       16. A method, comprising:
 causing, by a controller, pumping by a fluid pump of a hydraulic fracturing system; 
 causing, by the controller, opening of a control valve to cause fluid to flow through a recirculation circuit that directs the fluid from an outlet of the fluid pump to an inlet of the fluid pump,
 the recirculation circuit including the control valve and a choke valve; 
 
 obtaining, by the controller, information indicating a pressure of the fluid flowing through the recirculation circuit downstream of the control valve and the choke valve; and 
 causing, by the controller and based on the pressure of the fluid, actuation of the choke valve to maintain the pressure of the fluid below a threshold, wherein the threshold is based on a pressure containment capability of the inlet of the fluid pump. 
 
     
     
       17. The method of  claim 16 , wherein causing actuation of the choke valve to maintain the pressure of the fluid below the threshold comprises:
 causing increasing of fluid flow through the choke valve to maintain the pressure of the fluid at a maximum pressure that is below the threshold. 
 
     
     
       18. The method of  claim 16 , wherein causing actuation of the choke valve to maintain the pressure of the fluid below the threshold comprises:
 causing decreasing of fluid flow through the choke valve to maintain the pressure of the fluid below the threshold. 
 
     
     
       19. The method of  claim 16 , wherein a pressure containment capability of the outlet of the fluid pump is greater than the pressure containment capability of the inlet of the fluid pump. 
     
     
       20. The method of  claim 19 , further comprising:
 determining, by the controller, a difference between the pressure of the fluid and the threshold,
 wherein the actuation of the choke valve is based on the difference.